This thesis investigates evidence for social organisation and identities within the communities of Later Iron Age and early Roman Cornwall. The spatiotemporal analyses employed for these investigations derive from recognition that perceptions of time and the use of space are inherently linked and examine both factors as active constituents of one another. These analyses are used to propose a relationship between on-site location of structured deposits and the age of material within these deposits; this is argued to relate directly to the construction and reproduction of social identities at varying scales. 'Aged' deposits associated with enclosure banks and ancient landscape features are seen as linked to the reproduction of wider community identities, based upon notions of distant kinships, and associated with temporary collectives of people as part of local transhumant practices. In contrast, more recent material culture associated with structural walls that define the 'household' - the regular unit of social reproduction, are seen as reflecting the reiteration of household identities and kin-based genealogies. These insights are used to reinterpret the nature of social organisation in Cornwall in the Later Iron Age and early Roman periods. Based on the differential function of various site 'types' in terms of the intensity of use and the scale of social group, a heterarchical social structure dominated by extended households is proposed. The study also explores some more general concerns regarding the scales of identity and group organisation generated by the interpretation of later prehistoric remains, with particular reference to the notion of 'western Atlantic identities' during the European Iron Age.